แบบจำลองการปนเปื้อนของไนเตรทในน้ำบาดาลบริเวณศูนย์ศึกษาการพัฒนาห้วยทรายอันเนื่องมาจากพระราชดำริ และบริเวณใกล้เคียง อำเภอชะอำ จังหวัดเพชรบุรี / ปัณชญา กรุดสาท = Nitrate contamination model of groundwater in Huay Sai royal development study center and adjacent areas, Amphoe Cha-am, Changwat Phetchaburi / Panchaya Krutsat
Nowadays a lot of chemicals are widely used in human activities, such as community, agriculture and industry. When using in excessive amounts, they can lead to soil and groundwater contamination. The study area is Huay Sai Royal Development Study Center where lacks of surface water, groundwater thus is the major source for the local community. However, the quality of groundwater may be not appropriate for consumption due to nitrate contamination. The objective of this study was to simulate groundwater flow and nitrate contamination in this area by using the mathematical models, so-called Visual MODFLOW. The groundwater flow modeling was calibrated and then verified with measured groundwater levels (from August 2011 to October 2014) in both the steady and transient states with RMS ranging from 5.88 – 9.49 m. According to the calibration and verification result, the main groundwater aquifers, flood-plain deposit aquifer, Qfd, has the highest hydraulic conductivity (K) of 23.76 m/day. The nitrate contamination was also well fitted with observed nitrate concentrations (from October 2014 to February 2015) with RMS ranging from 0.42 – 3.58 mg/L. The model revealed that groundwater flows from the recharge zone in high land to discharge zone located in the center of groundwater basin where was found high amount of nitrate contaminated in the groundwater due to slow groundwater flow and intensively agricultural areas. Finally, based on the sensitivity analysis, K is the most sensitive parameters affecting groundwater level and nitrate concentration.
